Formation of oxidation-resistant seed layer for interconnect applications

ABSTRACT

An interconnect structure of the single or dual damascene type and a method of forming the same, which substantially reduces the surface oxidation problem of plating a conductive material onto a noble metal seed layer are provided. In accordance with the present invention, a hydrogen plasma treatment is used to treat a noble metal seed layer such that the treated noble metal seed layer is highly resistant to surface oxidation. The inventive oxidation-resistant noble metal seed layer has a low C content and/or a low nitrogen content.

FIELD OF THE INVENTION

The present invention relates to a semiconductor structure and a methodof fabricating the same. More particularly, the present inventionrelates to an interconnect structure of the single or dual damascenetype in which an oxidation-resistant noble metal seed layer is employed.The present invention also relates to a method of fabricating such asemiconductor structure.

BACKGROUND OF THE INVENTION

Generally, semiconductor devices include a plurality of circuits whichform an integrated circuit fabricated on a semiconductor substrate. Acomplex network of signal paths will normally be routed to connect thecircuit elements distributed on the surface of the substrate. Efficientrouting of these signals across the device requires formation ofmultilevel or multilayered schemes, such as, for example, single or dualdamascene wiring structures. The wiring structure typically includescopper, Cu, since Cu based interconnects provide higher speed signaltransmission between large numbers of transistors on a complexsemiconductor chip as compared with aluminum, Al, -based interconnects.

Within a typical interconnect structure, metal vias run perpendicular tothe semiconductor substrate and metal lines run parallel to thesemiconductor substrate. Further enhancement of the signal speed andreduction of signals in adjacent metal lines (known as “crosstalk”) areachieved in today's IC product chips by embedding the metal lines andmetal vias (e.g., conductive features) in a dielectric material having adielectric constant of less than silicon dioxide.

In current technologies, physical vapor deposited (PVD) Ta(N) and PVD Cuseed layers are used as a Cu diffusion barrier and plating seed,respectively, for advanced interconnect applications. However, withdecreasing critical dimension CD, it is expected that PVD baseddeposition techniques will run into conformality and step coverageissues. These, in turn, will lead to fill issues at plating such as, forexample, center and edge voids, which cause reliability concerns andyield degradation. One way to avoid this potential issue is to reducethe overall thickness of PVD deposited material, and utilizes a singlelayer of liner material as both the diffusion barrier and the platingseed layer.

Another way to avoid this potential issue is the use of chemical vapordeposition (CVD) or atomic layer deposition (ALD) technologies whichresults in better step coverage and conformality than the one from a PVDdeposition process. CVD/ALD deposited Ru and Ir have the potential ofreplacing current PVD based barrier/plating seed layers for advancedinterconnect applications.

However, an issue that exists for the direct plating of Cu on Ru (oranother like noble metal, i.e., a metal from Group VIIIA of the PeriodicTable of Elements) is the tendency of the surface to oxidize on exposureto air which results in an increased electrical conductivity, possibly adecrease in the uniformity of the electrical conductivity across awafer, and possibly adhesion. The noble metal surface oxidation leads toproblems in subsequent Cu electroplating process. Apart from theextremely poor fill of patterned structures, insufficient adhesion of Cuto a surface oxide poses electromigration and stress reliabilityconcerns. Known solutions involve the use of processes such as forminggas annealing to reduce the surface oxide before plating. Drawbacks ofthese prior art techniques include, for example: 1) a time window (Qtime) exists within which reduced wafers have to be plated before thesurface oxide grows again, and 2) increased manufacturing cost due torequire tooling for the reducing process, and increased raw processtime.

U.S. Pat. Nos. 5,486,262 to Datta et al., 6,432,821 to Dubin et al., and6,881,318 to Hey et al. are some prior art examples describing thedirect plating of Cu onto a noble metal. Although such examples ofdirect plating exist, these prior art direct plating processes alsosuffer the above mentioned surface oxidation problem.

In view of the surface oxidation problem mentioned above for prior artdirect plating methods, there is a continued need to provide a directplating method that can be used for fabricating interconnect structureswhere the surface oxidation of the noble metal seed layer has beensubstantially reduced and/or eliminated.

SUMMARY OF THE INVENTION

The present invention provides an interconnect structure of the singleor dual damascene type and a method of forming the same, whichsubstantially reduces or eliminates the surface oxidation problem thatis exhibited by prior art interconnect structures where a noble metalseed layer has been employed. In accordance with the present invention,this objective is achieved by utilizing a hydrogen plasma treatmentprocess which is performed on the surface of the noble metal seed layerprior to deposition of Cu or another like interconnect conductivematerial. The method of the present invention can reduce the surfacecarbon of the noble metal seed layer to about 2 atomic percent or less,similarly, the surface nitrogen content is about 3 atomic percent orless. Also, the surface concentration of oxygen is less than about 3atomic percent.

It is noted that the method of the present invention significantlyreduces the surface carbon content in the noble metal seed layer. It isalso noted that many CVD and ALD processes will not give a very puremetal. The residual carbonaceous material on the surface is prone to beoxidized and chemically change upon exposure to the atmosphere, which asa result will make the noble metal seed layer have a very differentsurface chemistry, such as direct palatability.

In broad terms, the invention provides a semiconductor structurecomprising a film stack including an oxidation-resistant noble metalseed layer sandwiched between a substrate and a conductivemetal-containing material.

In more specific terms, an interconnect structure is provided thatcomprises: a dielectric material including at least one opening therein;a diffusion barrier located within said at least one opening; anoxidation-resistant noble metal seed layer located on said diffusionbarrier; and an interconnect conductive material located within the atleast one opening.

The present invention contemplates closed-via bottom structures,open-via bottom structures and anchored-via bottom structures.

In a preferred embodiment of the present invention, a Cu interconnectstructure is provided that includes: a dielectric material including atleast one opening therein; a diffusion barrier located within said atleast one opening; an oxidation-resistant noble metal seed layer locatedon said diffusion barrier; and a Cu interconnect metal located withinthe at least one opening.

In addition to providing the aforementioned interconnect structures, thepresent invention also provides a method of fabricating the same. Ingeneral terms, the method of the present invention includes: forming atleast one opening in a dielectric material; forming a diffusion barrieron exposed wall portions of said dielectric material within said atleast one opening; forming an oxidation-resistant seed layer on saiddiffusion barrier; and forming an interconnect conductive materialwithin said at least one opening.

In broader terms, the present invention provides a method that includesforming a noble metal seed layer on a surface of a substrate; treatingsaid noble metal seed layer in a hydrogen plasma to provide anoxidation-resistant noble metal seed layer; and forming a conductivematerial on said oxidation-resistant noble metal seed layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial representation (through a cross sectional view)illustrating an interconnect structure through initial stages of theinventive method wherein at least one opening is provided in adielectric material.

FIG. 2 is a pictorial representation (through a cross sectional view)illustrating the interconnect structure of FIG. 1 after formation of adiffusion barrier inside the at least the one opening.

FIG. 3 is a pictorial representation (through a cross sectional view)illustrating the interconnect structure of FIG. 2 after formation of anoble metal seed layer.

FIG. 4 is a pictorial representation (through a cross sectional view)illustrating the interconnect structure of FIG. 3 after subjecting saidnoble metal seed layer to a hydrogen plasma treatment process.

FIG. 5 is a pictorial representation (through a cross sectional view)illustrating the interconnect structure of FIG. 4 after formation of aconductive material within the at least one opening and subsequentplanarization. In the illustrated structure, a closed-via bottom isillustrated on the right hand side.

FIGS. 6A and 6B are pictorial representations (through cross sectionalviews) depicting alternative interconnect structure that can be formedutilizing the method of the present invention; FIG. 6A includes aninterconnect structure with an open-via bottom structure, while FIG. 6Bincludes an interconnect structure with an anchored-via bottomstructure.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The present invention, which provides an interconnect structureincluding an oxidation-resistant noble metal seed layer and a method offabricating the same, will now be described in greater detail byreferring to the following discussion and drawings that accompany thepresent application. The drawings of the present application, which arereferred to herein below in greater detail, are provided forillustrative purposes and, as such, they are not drawn to scale.

The process flow of the present invention begins with providing theinitial interconnect structure 10 shown in FIG. 1. Specifically, theinitial interconnect structure 10 shown in FIG. 1 comprises a multilevelinterconnect including a lower interconnect level 12 and an upperinterconnect level 16 that are separated in part by dielectric cappinglayer 14. The lower interconnect level 12, which may be located above asemiconductor substrate including one or more semiconductor devices,comprises a first dielectric material 18 having at least one conductivefeature (i.e., conductive region) 20 that is separated from the firstdielectric material 18 by a barrier layer 22. The upper interconnectlevel 16 comprises a second dielectric material 24 that has at least oneopening located therein. In FIG. 1, two openings are shown; referencenumber 26 denotes a line opening for a single damascene structure, andreference numeral 28A and 28B denote a via opening and a line opening,respectively for a dual damascene structure. Although FIG. 1 illustratesa separate line opening and an opening for a via and a line, the presentinvention also contemplates cases in which only the line opening ispresent or cases in which the opening for the combined via and line ispresent.

The initial interconnect structure 10 shown in FIG. 1 is made utilizingstandard interconnect processing which is well known in the art. Forexample, the initial interconnect structure 10 can be formed by firstapplying the first dielectric material 18 to a surface of a substrate(not shown). The substrate, which is not shown, may comprise asemiconducting material, an insulating material, a conductive materialor any combination thereof. When the substrate is comprised of asemiconducting material, any semiconductor such as Si, SiGe, SiGeC, SiC,Ge alloys, GaAs, InAs, InP and other III/V or II/VI compoundsemiconductors may be used. In addition to these listed types ofsemiconducting materials, the present invention also contemplates casesin which the semiconductor substrate is a layered semiconductor such as,for example, Si/SiGe, Si/SiC, silicon-on-insulators (SOIs) or silicongermanium-on-insulators (SGOIs).

When the substrate is an insulating material, the insulating materialcan be an organic insulator, an inorganic insulator or a combinationthereof including multilayers. When the substrate is a conductingmaterial, the substrate may include, for example, polySi, an elementalmetal, alloys of elemental metals, a metal silicide, a metal nitride orcombinations thereof including multilayers. When the substrate comprisesa semiconducting material, one or more semiconductor devices such as,for example, complementary metal oxide semiconductor (CMOS) devices canbe fabricated thereon.

The first dielectric material 18 of the lower interconnect level 12 maycomprise any interlevel or intralevel dielectric including inorganicdielectrics or organic dielectrics. The first dielectric material 18 maybe porous or non-porous. Some examples of suitable dielectrics that canbe used as the first dielectric material 18 include, but are not limitedto: SiO₂, silsesquixoanes, C doped oxides (i.e., organosilicates) thatinclude atoms of Si, C, O and H, thermosetting polyarylene ethers, ormultilayers thereof. The term “polyarylene” is used in this applicationto denote aryl moieties or inertly substituted aryl moieties which arelinked together by bonds, fused rings, or inert linking groups such as,for example, oxygen, sulfur, sulfone, sulfoxide, carbonyl and the like.

The first dielectric material 18 typically has a dielectric constantthat is about 4.0 or less, with a dielectric constant of about 2.8 orless being even more typical. These dielectrics generally have a lowerparasitic crosstalk as compared with dielectric materials that have ahigher dielectric constant than 4.0. The thickness of the firstdielectric material 18 may vary depending upon the dielectric materialused as well as the exact number of dielectrics within the lowerinterconnect level 12. Typically, and for normal interconnectstructures, the first dielectric material 18 has a thickness from about200 to about 450 nm.

The lower interconnect level 12 also has at least one conductive feature20 that is embedded in (i.e., located within) the first dielectricmaterial 18. The conductive feature 20 comprises a conductive regionthat is separated from the first dielectric material 18 by a barrierlayer 22. The conductive feature 20 is formed by lithography (i.e.,applying a photoresist to the surface of the first dielectric material18, exposing the photoresist to a desired pattern of radiation, anddeveloping the exposed resist utilizing a conventional resistdeveloper), etching (dry etching or wet etching) an opening in the firstdielectric material 18 and filling the etched region with the barrierlayer 22 and then with a conductive material forming the conductiveregion. The barrier layer 22, which may comprise Ta, TaN, Ti, TiN, Ru,RuN, W, WN or any other material that can serve as a barrier to preventconductive material from diffusing there through, is formed by adeposition process such as, for example, atomic layer deposition (ALD),chemical vapor deposition (CVD), plasma enhanced chemical vapordeposition (PECVD), physical vapor deposition (PVD), sputtering,chemical solution deposition, or plating.

The thickness of the barrier layer 22 may vary depending on the exactmeans of the deposition process as well as the material employed.Typically, the barrier layer 22 has a thickness from about 4 to about 40nm, with a thickness from about 7 to about 20 nm being more typical.

Following the barrier layer 22 formation, the remaining region of theopening within the first dielectric material 18 is filled with aconductive material forming the conductive feature 20. The conductivematerial used in forming the conductive feature 20 includes, forexample, polySi, a conductive metal, an alloy comprising at least oneconductive metal, a conductive metal silicide or combinations thereof.Preferably, the conductive material that is used in forming theconductive feature 20 is a conductive metal such as Cu, W or Al, with Cuor a Cu alloy (such as AlCu) being highly preferred in the presentinvention. The conductive material is filled into the remaining openingin the first dielectric material 18 utilizing a conventional depositionprocess including, but not limited to: CVD, PECVD, sputtering, chemicalsolution deposition or plating. After deposition, a conventionalplanarization process such as, for example, chemical mechanicalpolishing (CMP) can be used to provide a structure in which the barrierlayer 22 and the conductive feature 20 each have an upper surface thatis substantially coplanar with the upper surface of the first dielectricmaterial 18.

Although not specifically illustrated, the inventive method describedherein below (including noble metal seed layer deposition followed by aH₂ plasma process) can be used to provide the conductive feature 20,which includes an oxidation-resistant noble metal seed layer between theconductive feature 20 and the barrier layer 22. In such an embodiment,polysilicon is not used as the conductive material.

After forming the at least one conductive feature 20, the dielectriccapping layer 14 is formed on the surface of the lower interconnectlevel 12 utilizing a conventional deposition process such as, forexample, CVD, PECVD, chemical solution deposition, or evaporation. Thedielectric capping layer 14 comprises any suitable dielectric cappingmaterial such as, for example, SiC, Si₄NH₃, SiO₂, a carbon doped oxide,a nitrogen and hydrogen doped silicon carbide SiC(N,H) or multilayersthereof. The thickness of the capping layer 14 may vary depending on thetechnique used to form the same as well as the material make-up of thelayer. Typically, the capping layer 14 has a thickness from about 15 toabout 55 nm, with a thickness from about 25 to about 45 nm being moretypical.

Next, the upper interconnect level 16 is formed by applying the seconddielectric material 24 to the upper exposed surface of the capping layer14. The second dielectric material 24 may comprise the same ordifferent, preferably the same, dielectric material as that of the firstdielectric material 18 of the lower interconnect level 12. Theprocessing techniques and thickness ranges for the first dielectricmaterial 18 are also applicable here for the second dielectric material24. Next, at least one opening is formed into the second dielectricmaterial 24 utilizing lithography, as described above, and etching. Theetching may comprise a dry etching process, a wet chemical etchingprocess or a combination thereof. The term “dry etching” is used hereinto denote an etching technique such as reactive-ion etching, ion beametching, plasma etching or laser ablation. In FIG. 1, two openings areshown; reference number 26 denotes a line opening for a single damascenestructure, and reference numeral 28A and 28B denote a via opening and aline opening, respectively for a dual damascene structure. It is againemphasized that the present invention contemplates structures includingonly opening 26 or openings 28A and 28B.

In the instances when a via opening 28A and a line opening 28B areformed, the etching step also removes a portion of the dielectriccapping layer 14 that is located atop the conductive feature 20 in orderto make electrical contact between interconnect level 12 and level 16.

Next, a diffusion barrier 30 having Cu diffusion barrier properties isprovided by forming the diffusion barrier 30 on exposed surfaces(including wall surfaces within the opening) on the second dielectricmaterial 24. The resultant structure is shown, for example, in FIG. 2.The diffusion barrier 30 comprises a same or different material as thatof barrier layer 22. Thus, diffusion barrier 30 may comprise Ta, TaN,Ti, TiN, Ru, RuN, RuTa, RuTaN, W, WN or any other material that canserve as a barrier to prevent a conductive material from diffusing therethrough. Combinations of these materials are also contemplated forming amultilayered stacked diffusion barrier. The diffusion barrier 30 isformed utilizing a deposition process such as, for example, atomic layerdeposition (ALD), chemical vapor deposition (CVD), plasma enhancedchemical vapor deposition (PECVD), physical vapor deposition (PVD),sputtering, chemical solution deposition, or plating.

The thickness of the diffusion barrier 30 may vary depending on thenumber of material layers within the barrier, the technique used informing the same as well as the material of the diffusion barrieritself. Typically, the diffusion barrier 30 has a thickness from about 4to about 40 nm, with a thickness from about 7 to about 20 nm being evenmore typical.

FIG. 3 shows the structure of FIG. 2 after formation of noble metal seedlayer 32 atop the diffusion barrier 30. The noble metal seed layer 32 iscomprised of a metal or metal alloy from Group VIIIA of the PeriodicTable of Elements. Examples of suitable Group VIIIA elements for thenoble metal seed layer include, but are not limited to: Ru, Ir, Rh, Pt,Pd and alloys thereof. In some embodiments, it is preferred to use Ru,Ir or Rh as the noble metal seed layer 32.

The noble metal seed layer 32 is formed by a conventional depositionprocess including, for example, chemical vapor deposition (CVD), plasmaenhanced chemical vapor deposition (PECVD), atomic layer deposition(ALD), plating, sputtering and physical vapor deposition (PVP). Thethickness of the noble metal seed layer 32 may vary depending on numberof factors including, for example, the compositional material of thenoble metal seed layer 32 and the technique that was used in forming thesame. Typically, the noble metal seed layer 32 has a thickness fromabout 0.5 to about 10 nm, with a thickness of less than 6 nm being evenmore typical.

FIG. 4 shows the resultant structure formed after subjecting the noblemetal seed layer 32 to a hydrogen (H₂) plasma treatment process, whichforms an oxidation-resistant noble metal seed surface region 34 on layer32. It is noted that the noble metal seed layer 32 together with theoxidation-resistant noble metal seed surface region 34 form theinventive oxidation-resistant noble metal seed layer. The H₂ plasmaprocess includes providing a plasma of hydrogen, H₂, using a hydrogensource such as, for example, molecular or, more preferably, atomichydrogen. The hydrogen plasma is a neutral, highly ionized hydrogen gasthat consists of neutral atoms or molecules, positive ions and freeelectrons. Ionization of the hydrogen source is typically carried out ina reactor chamber in which the ionization process is achieved bysubjecting the source to strong DC or AC electromagnetic fields.Alternatively, the ionization of the hydrogen source is performed bybombarding the gate atoms with an appropriate electron source. Inaccordance with a preferred embodiment of the present invention, thehydrogen plasma process used to provide the oxidation-resistant noblemetal seed surface region 34 is performed at a temperature of from about20° to about 200°. Other temperatures can also be used as long as thetemperature of the H₂ plasma process provides an oxidation-resistantnoble metal seed surface region 34.

The term “oxidation-resistant noble metal seed layer” is used throughoutthe present application to denote a seed layer that contains a noblemetal or an alloy of a noble metal wherein a surface oxide does not formthereon during subsequent expose to air. It is again emphasized thatsurface region 34 and layer 32 form the inventive oxidation-resistantnoble metal seed layer. As compared to a conventional noble metalsurface without receiving the claimed method for surface treatment, thepresent invention can reduce the surface carbon of the noble metal toabout 2 atomic percent or less, similarly, the surface nitrogen contentis about 3 atomic percent or less. Also, the surface concentration ofoxygen is less than about 3 atomic percent.

FIG. 5 shows the structure after forming an interconnect conductivematerial 38 within the at least one opening. The structure shown in FIG.5 represents one possible embodiment of the present invention, while thestructures shown in FIGS. 6A and 6B represent other possible embodimentsof the present invention. In FIG. 5, a closed-via bottom structure isshown. In FIG. 6A, the interconnect conductive material 38 is formedwithin an open-via bottom structure. The open-via structure is formed byremoving the diffusion barrier from the bottom of via 28A utilizing ionbombardment or another like directional etching process prior todeposition of the other elements. In FIG. 6B, an anchored-via bottomstructure is shown. The anchored-via bottom structure is formed by firstetching a recess into the conductive feature 20 utilizing a selectiveetching process. The diffusion barrier 30 is then formed and it isselectively removed from the bottom portion of the via and recess byutilizing one of the above-mentioned techniques. The other elements,i.e., oxidation-resistant noble metal seed layer (i.e., surface region34 and layer 32) and conductive material 38, are then formed within theopening as described herein.

In each of the illustrated structures, the interconnect conductivematerial 38 may comprise the same or different, preferably the same,conductive material (with the proviso that the conductive material isnot polysilicon) as that of the conductive feature 20. Preferably, Cu,Al, W or alloys thereof are used, with Cu or AlCu being most preferred.The conductive material 38 is formed utilizing the same depositionprocessing as described above in forming the conductive feature 20 andfollowing deposition of the conductive material, the structure issubjected to planarization. The planarization process removes thediffusion barrier 30, the plating seed layer 32, oxidation-resistantnoble metal seed layer 34, and conductive material 38 that is presentabove the upper horizontal surface of the upper interconnect level 16.

The method of the present application is applicable in forming suchoxidation-resistant seed layer in any one or all of the interconnectlevels of an interconnect structure. The same basic processing steps canbe used to form other semiconductor structures, such as, for example, afield effect transistor, in which the oxidation-resistant metal seedlayer is present.

The following example is provided to illustrate the broad concept of thepresent invention and to illustrate some advantages that are obtainedtherefrom.

EXAMPLE

Two copper-capped ruthenium films were analyzed by Secondary Ion MassSpectrometry (SIMS), an analytical method to measure impurities such ascarbon. One film was capped with copper without treatment(representative of the prior art); and the second was exposed to a H₂plasma (representative of the present invention) before copper capping.The H₂ plasma treatment included a certain amount of N₂, e.g., from 0%to about 85%. Capping with a physical-vapor deposition copper film aftera controlled time was done to seal any contaminants out of the rutheniumsurface. So capped, the ruthenium and ruthenium surface would berepresentative of a fresh sample, i.e., representing the impurities ofthe film in the air-exposure time scale as such a film would beprocessed in a microelectronic manufacturing environment.

SIMS (secondary ion mass spectroscopy) shows that the plasma treatmentsignificantly lowers the carbon content of the ruthenium film (in thebulk of the Ru as well as the film surface.). No change in hydrogen inthe copper or in the ruthenium was observed. This shows no need toevaluate any effects of residual hydrogen. Also, only a slight change inthe oxygen content of films were observed; one profile showed a slightlessening of signal at the top surface of the Ru. However, anylessening, or changing of bonding state from chemical reduction, may bea potential, and expected, benefit of the present invention, or may be abenefit for other film types. The above data clearly shows that themethod of the present invention significantly cleans the ruthenium film.Getting rid of impurities such as carbon, particularly near the surface,is expected to improve the ability to plate films such as copper on thefilm; to improve consistency in a subsequent chemical-mechanical polish.

While the present invention has been particularly shown and describedwith respect to preferred embodiments thereof, it will be understood bythose skilled in the art that the foregoing and other changes in formsand details may be made without departing from the spirit and scope ofthe present invention. It is therefore intended that the presentinvention not be limited to the exact forms and details described andillustrated, but fall within the scope of the appended claims.

1. An interconnect structure comprising: a dielectric material includingat least one opening therein; a diffusion barrier located within said atleast one opening; an oxidation-resistant noble metal seed layer locatedon said diffusion barrier, said oxidation-resistant noble metal seedlayer comprises a noble metal seed layer having an upper surface regionthat is resistant to oxidation; and an interconnect conductive materiallocated within the at least one opening atop said oxidation-resistantnoble metal seed layer.
 2. The interconnect structure of claim 1 whereinsaid dielectric material is one of SiO₂, a silsesquioxane, a C dopedoxide that includes atoms of Si, C, O and H, and a thermosettingpolyarylene ether.
 3. The interconnect structure of claim 1 wherein saidat least one opening is a line opening, a combined line opening and viaopening, or combinations thereof.
 4. The interconnect structure of claim1 wherein said oxidation-resistant noble metal seed layer comprises ametal or metal alloy from Group VIIIA of the Periodic Table of Elements.5. The interconnect structure of claim 4 wherein saidoxidation-resistant noble metal seed layer comprises Ru, Ir, or Rh. 6.The interconnect structure of claim 1 wherein said upper surface regionhas a carbon content of about 2 atomic percent or less.
 7. Theinterconnect structure of claim 1 wherein said upper surface region hasa nitrogen content of about 3 atomic percent or less.
 8. Theinterconnect structure of claim 1 wherein said diffusion barriercomprises Ta, TaN, Ti, TiN, Ru, RuN, RuTa, RuTaN, W, WN or any othermaterial that can serve as a barrier to prevent conductive material fromdiffusing there through.
 9. The interconnect structure of claim 1wherein said interconnect conductive material is one of a conductivemetal, an alloys comprising at least one conductive metal, and aconductive metal silicide.
 10. The interconnect structure of claim 9wherein said interconnect conductive material is a conductive metalselected from the group consisting of Cu, Al, W and AlCu.
 11. Theinterconnect structure of claim 1 wherein said interconnect conductivematerial comprises Cu and said oxidation-resistant noble metal seedlayer comprises Ru, Ir or Rh.
 12. The interconnect structure of claim 1wherein said interconnect conductive material is present in an open-viabottom structure, an anchored-via bottom structure, or a closed-bottomvia structure
 13. A semiconductor structure comprising: a film stackincluding an oxidation-resistant noble metal seed layer sandwichedbetween a substrate and a conductive metal-containing material, saidoxidation-resistant noble metal seed layer comprises a noble metal seedlayer having an upper surface region that is resistant to oxidation.14-20. (canceled)
 21. An interconnect structure comprising: a dielectricmaterial including at least one opening therein; a diffusion barrierlocated within said at least one opening; an oxidation-resistant noblemetal seed layer located on said diffusion barrier, saidoxidation-resistant noble seed layer has a surface region having acarbon content of about 2 atomic percent or less; and an interconnectconductive material located within the at least one opening atop saidoxidation-resistant noble metal seed layer.
 22. An interconnectstructure comprising: a dielectric material including at least oneopening therein; a diffusion barrier located within said at least oneopening; an oxidation-resistant noble metal seed layer located on saiddiffusion barrier, said oxidation-resistant noble seed layer has asurface region having a nitrogen content of about 3 atomic percent orless; and an interconnect conductive material located within the atleast one opening atop said oxidation-resistant noble metal seed layer.